Simulation-based assessment of Microbiological Criteria on Salmonella in poultry meat

A simulation exercise was performed to contribute to the assessment of the impact of Salmonella spp. on public health. The aim of this simulation approach was to investigate the effect of the prevalence of contaminated broiler carcasses at slaughterhouse level, after chilling but before further processing, on the probability of meeting the Microbiological Process Hygiene Criteria (MPHC) as defined by Regulation (EC) No 2073/2005 and its amendments. Using different scenarios it was possible to simulate the implementation of the monitoring procedures at slaughterhouse level and to relate carcass prevalence to the probability of meeting the criteria and vice versa. As an example, considering a true prevalence of contaminated carcasses at the slaughterhouse equal to 5%, assuming a test with sensitivity 90% and specificity 100% and a constant prevalence over time, the probability of meeting the criteria is equal to 68.45%. Furthermore, it is also possible for an observed frequency of meeting the microbiological criteria at a given slaughterhouse, e.g. equal to 95.54%, to estimate the underlying true prevalence of contaminated carcasses, which is equal to 3% in the considered example.
The results from these simulations will contribute to the analysis of the outcome from the EU baseline survey at slaughterhouse level (EFSA-Q-2010-00687).